1. Field of the Invention
The present invention generally relates to an apparatus equipped removably with a scanner unit (also referred to as a scanner-equipped apparatus) in which a base apparatus or base unit such as a personal computer, a word processor or the like incorporating therein a printer unit is combined detachably with a scanner unit so that the scanner unit itself can also be used independently as a so-called handy scanner. By way of example, as a typical one of the scanner-equipped apparatus, there may be mentioned a printer/scanner combination apparatus which is composed of a printer unit and a scanner unit combined integrally and mutually detachably and which provides advantages that the space demanded for the installation of the apparatus can be reduced when compared with the space required for installing separately the printer unit and the scanner unit and that the printer/scanner combination apparatus can be manufactured at relatively low costs. Thus, the present invention is particularly concerned with a printer/scanner combination apparatus which includes a printer unit and a scanner unit combined detachably such that the scanner unit can be detached to be used as the handy scanner, to thereby enhance the utility of the scanning function while ensuring high manipulatabilty and serviceability for maintenance of the apparatus.
2. Description of Related Art
In recent years, in the field of data processing with the personal computer, there arises an increasing tendency of processing image, graphics and the like data, which is accompanied with rapid spreading of the scanner apparatus for fetching the image data.
In general, the personal computer system is comprised of a main body, a display unit, a keyboard, a printer, etc. Consequently, for the installation of the personal computer system, a considerably large space is demanded. Such being the circumstances, user who bought a scanner will often bother his or her head over the place where the scanner is to be installed. Furthermore, although the scanner is commercially available at remarkably low price at present, purchase of the scanner means not a little burden on the consumers.
Under the circumstances, there have been developed various scanner-equipped printer apparatuses in which a sensor is mounted on a carriage of the printer, wherein image reading operation is carried out by making use of the sheet feed mechanism of the printer for feeding an image document sheet (i.e., paper or the like sheet having text, a picture or graphics recorded thereon) in efforts to implement the scanner at low costs while mitigating the space demand for the installation of the scanner.
However, in the case of the conventional scanner-equipped printer apparatuses known heretofore, the sheet feeding mechanism is used in common for both the scanning function and the printing function. Consequently, it has been impossible to use both the functions at the same time. Further known is such a printer/scanner combination apparatus in which the reader unit provided for realizing the scanning function can be detached so as to be used as a so-called handy scanner. However, because the conventional reader unit includes no driving mechanism, the handy scanner can be operated only manually. In order to allow the handy scanner to operate automatically, it is required to provide a driving mechanism dedicated for the handy scanner. However, in the conventional apparatus, the driving mechanism for the handy scanner is left unused in the state in which the handy scanner is mounted on the printer unit. Thus, in the conventional printer/scanner combination apparatus, the efficiency of hardware utilization is low, which in turn means that the cost-performance of the conventional printer/scanner combination apparatus is poor.